Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
197 words
A method for detecting and separating shadow of moving objects in a sequence of digital images, comprising the steps of: a) determining a sequence of background images from the sequence of digital images, said sequence of background images containing only the non-moving image background of the sequence of images but not the moving objects; b) determining, for extracting object edges, in each case an edge gray-value image for each image of the sequence of digital images and for each respective corresponding background image of the sequence of background images; c) determining, by means of vertical or horizontal projection of said edge gray-value images, corresponding vertical or horizontal edge histograms in each case for the edge gray-value images; d) eliminating edges which do not belong to moving objects or shadows, in that edge histograms of a background image are subtracted from corresponding edge histograms of an image, at a common instant in time, of the sequence of digital images, thereby forming differential edge histograms; e) subjecting the differential edge histograms to a threshold value discrimination, to eliminate those edges which do not correspond to actual moving objects but which do correspond to a shadow of a moving object.
Claim 2
Independent Claim
197 words
A method for detecting and separating shadow of moving objects in a sequence of digital images, comprising the steps of: a) determining a sequence of background images from the sequence of digital images, said sequence of background images containing only the non-moving image background of the sequence of images but not the moving objects; b) determining, for extracting object edges, in each case an edge gray-value image for each image of the sequence of digital images and for each respective corresponding background image of the sequence of background images; c) determining, by means of vertical or horizontal projection of said edge gray-value images, corresponding vertical or horizontal edge histograms in each case for the edge gray-value images; d) eliminating edges which do not belong to moving objects or shadows, in that edge histograms of a background image are subtracted from corresponding edge histograms of an image, at a common instant in time, of the sequence of digital images, thereby forming differential edge histograms; e) subjecting the differential edge histograms to a threshold value discrimination, to eliminate those edges which do not correspond to actual moving objects but which do correspond to a shadow of a moving object.
Claim 3
Dependent Claim
24 words
The method as claimed in claim 1, wherein the edge gray-value images are put into binary form before the determination of the edge histograms.
Claim 4
Dependent Claim
37 words
The method as claimed in claim 1, wherein, before carrying out steps b) to e) image regions are determined which correspond to moving objects and wherein steps b) to e) are applied only to these image regions.
Claim 5
Dependent Claim
44 words
The method as claimed in claim 1, wherein the method further comprises forming a time sequence of edge histograms from the edge histograms which belong to a common moving object, and improving elimination of shadow edges by identification and time tracking of corresponding edges.
Claim 6
Dependent Claim
34 words
The method as claimed in claim 1, wherein the method further comprises elimination of shadow edges by evaluating a preknowledge about a lateral position of the shadow edges with reference to corresponding object edges.
Claim 7
Dependent Claim
60 words
The method as claimed in claim 4, wherein the method further comprises elimination of shadow edges by evaluating a preknowledge about a lateral position of the shadow edges with reference to corresponding object edges, and wherein the preknowledge about the lateral position of the shadow edges is learned in an adaptive manner using the time sequence and is continuously checked.